Man discovers he's not the father of his baby — his unborn twin is

Ally Hirschlag is a producer/actor/writer who lives in Brooklyn, NY and buys way too many toys for her cats. She contributes to several publications, including Bustle, and The Nerve, and enjoys writing about all things woman. In her spar...

Man learns his unborn twin is biologically the father of his baby

This sounds like something out of a soap opera storyline, but in fact it is true. After this 34-year-old man took a paternity test, he learned that not only was he not the father of his newborn son, but somehow his unborn twin was.

If you're confused, don't worry, you're not alone. The sort-of parents, who have chosen to remain anonymous despite the fact that they're an awesome medical anomaly, went to a fertility clinic back in June 2014 for help to conceive a child. Not long after, the wife became pregnant and gave birth to a perfectly healthy baby boy. However, upon having regular blood work done, the parents noticed something odd: Their son didn't match their blood types.

So the father took an at-home paternity test and received even more troubling results — he appeared to not be the father of his son. Naturally the parents were confused and upset. They thought the clinic had somehow used the wrong sperm during insemination. So they decided to get a more precise paternity test to make sure they weren't blowing a false negative out of proportion. However, sure enough, the second test came back with the same results — the man's DNA did not match his son's.

Needless to say, there were probably a lot of accusations thrown back and forth between the mother and "father" before the couple returned to the clinic, demanding absolution. The clinic assured them there was no way the sperm came from a different donor, because the "father" was the only Caucasian man to give sperm the day his wife was inseminated, and their baby looks Caucasian.

Stumped by this news, the couple consulted a geneticist at Stanford University named Barry Starr. According to BuzzFeed News, he suggested they get a genetic ancestry test. This came back with the most shocking results yet — the father was actually his son's uncle. While this sounds like the catalyst to a big, melodramatic reveal — that the mother was actually sleeping with her husband's brother — the truth is much more interesting. The father is his own twin.

What this means is, he shared a womb with a twin, but that twin did not fully develop, and as a result, he absorbed his twin's DNA. This incredibly rare phenomenon is called a chimera and is believed to happen every 1 in 8 single births, but that's just an estimate, because it's not often recorded. It can happen to both men and women, and it means that while you may have conceived a child, they won't follow your genetic makeup. Freaky, right?

This is the first case of a father failing a paternity test because he's a chimera. However, he's definitely not the first chimera to ever be reported. Another interesting chimera case surfaced back in 2002 when Karen Keegan needed a kidney transplant and learned that her children were not compatible with her blood type.

While chimeras are totally possible, their occurrence does not mean you shouldn't fly off the handle if you learn you're not the father of your child. It's much more likely that there's something your wife's not telling you than that you're actually your own twin.